I have been challenged to substantiate the following statement: The only conspiracy is one perpetrated by those with a financial interest in maintenance of the status quo; to encourage the continuing abdication of responsibility for a scientifically-inevitable problem that is already undeniably happening… So, here goes:

Oreskes and Conway’s book, Merchants of Doubt, sets out in great detail the way in which Jastrow, Singer and Seitz decided that, in the absence of Communists, they would fight Environmentalists instead: Oil Companies and Energy companies are only too pleased to fund their disinformation campaigns by bank-rolling organisations such as the George C. Marshall Institute and the Heartland Institute (and before them the Global Climate Coalition).

One of the greatest successes of these Merchants of Doubt has been to make the population at large distrust scientific authority in order to promote sales of the products of their paymasters and/or prevent them going into decline; or even from being banned.

Therefore, in roughly chronological order, they told us that:
smoking cigarettes is sophisticated;
smoking is not harmful;
organic pesticides are more effective than natural predators;
organic pesticides are safe;
CFC’s are not dangerous;
humanity is too insignificant to affect the atmosphere;
the hole in the ozone layer is not there;
CFC’s aren’t causing the hole in the ozone layer;
acid rain does not exist;
we are not causing acid rain;
we can’t afford to prevent acid rain;
pollution is preventing global warming; (this one was true – not that they cared)
humanity is too insignificant to affect climate;
the climate will not change faster than we can adapt to it;
the climate is not changing;
smoking does not cause cancer;
passive smoking is not dangerous; (see footnote below)
we are not causing the climate to change;
we cannot afford to prevent climate change;
climate change has stopped…